Renáta Szabóová

Antimicrobial activity of Enterococcus faecium ef 55 against Salmonella enteritidis in chicks.

The protective effect of Enterococcus faecium EF 55 against Salmonella enterica serovar Enteritidis phage type 4 (SE PT4) was studied in 1-day-old chicks. The EF 55 strain (isolated and characterised by the authors earlier) was applied daily (1.10(9) CFU/0.2 ml PBS) for 7 days. Oral inoculation of the SE PT4 strain was performed on day 8 in a single dose of 5.10(8) CFU/0.2 ml PBS. The experiment lasted for 21 days. Samples were collected on day 1 of the experiment to verify the absence of Salmonella, on day 8 to check colonisation of EF 55 and immunological status in experimental birds, and on days 2, 4, 6, 8 and 14 after SE PT4 infection of chicks. Strain EF 55 sufficiently colonised the digestive tract of chicks after 7 days of application. The highest numbers of EF 55 in the faeces of chicks were observed before SE infection and persisted to day 6 post infection (p.i.) in both the EF and EF+SE groups. PCR confirmed the identity of the EF 55 strain. The counts of SE PT4 strain in faeces of the EF+SE group were significantly reduced in comparison to those in the SE group on days 2 and 14 p.i. (P < 0.01). The significant reduction of salmonellae in the caecum was recorded at the end of the experiment (day 14 p.i.) in the EF+SE group in comparison to the SE group (P < 0.01). At day 4 p.i., colonies of S. Enteritidis PT4 were found in the liver of chicks of the SE group in a higher concentration than in chicks of the EF+SE group (P < 0.001). Salmonellae were isolated from the liver until days 8 and 6 p.i. in the SE and EF+SE groups, respectively. The mean values of actual lymphocyte subpopulations in the blood and the relative percentage of caecal intraepithelial lymphocyte subpopulations (CD4, CD8, CD44, TCR, MHC II and IgM) were not influenced at a statistically significant level by the application of the EF 55 and/or the SE PT4 strain. The results demonstrate the antimicrobial effect of E. faecium EF 55 against S. Enteritidis PT4.

Can enterocins affect phagocytosis and glutathione-peroxidase in rabbits?

The gastrointestinal microbiota in rabbits play an important role in protection against potential pathogens via the development of the mucosal immune system. The gut health, including the microbial and immunological stability, is often influenced by exogenous factors, mainly around the weaning period. Therefore, alternative strategies are required to improve the animal’s health. In this study, the diet of rabbits was supplemented with the semi-purified enterocins Ent 2019, Ent M and Ent 4231, produced by bacteriocinogenic strains with probiotic properties, rabbit-derived Enterococcus faecium CCM7420 and non rabbit-derived E. faecium strains AL41 and CCM4231. The phagocytic activity, index of phagocytic activity and the gluthatione-peroxidase enzyme activity in blood were determined during the Ents consumption and also 3 weeks after their cessation. At 21 days into the experiment the highest phagocytic activity was observed in rabbits receiving Ent M. A significant increase in phagocytosis was noted in rabbits with Ent 2019 over the entire experiment. Moreover, a lower gluthatione-peroxidase activity was measured in rabbits receiving Ent M and Ent 2019. No effect of Ent 4231 application on the tested parameters was recorded. The Ent M and Ent 2019 improved the digestive immunity and the host’s defense capacities by stimulating leucocyte phagocytosis, without oxidative stress induction in rabbits.

Decarboxylase‐positive Enterococcus faecium strains isolated from rabbit meat and their sensitivity to enterocins

Abstract Background The objective of the study was to determine sensitivity of Enterococcus faecium strains from rabbit meat to enterocins. Results Twenty‐five decarboxylase‐positive strains (from rabbit meat) allotted to the species E. faecium by genotypization and by MALDI TOF MS spectrometry identification (evaluation score value range 2.104–2.359; in the range for highly probable species identification‐score value 2.300–3.000 and secure probable species identification/probable species identification‐2.000–2.299) were studied. Seventeen strains were gelatinase positive. Although they did not produce histamine (HIS), spermidine, and spermine, they produce at least one among seven tested biogenic amines (BAs) in small amounts (2–10 mg/L) or up to very high amounts (>1000 mg/L). Putrescine was produced by two strains. These decarboxylase‐positive strains were sensitive to enterocins (Ents). All strains were sensitive to Ent 2019 and Ent 55 (inhibitory activity from 200 to 819 200 AU/mL). Twenty‐two strains were inhibited by Ent A(P) and Ent 4231; 20 strains were sensitive to Ent M. Conclusion Our results have spread the basic knowledge related to inhibitory spectrum of enterocins showing sensitivity of decarboxylase‐positive strains to enterocins. Protective possibilities of enterocins in meat processing were also indicated.

Enterocin 4231 produced by Enterococcus faecium CCM 4231 and its use in rabbits.

The aim of this experiment was to study the effect of Enterocin (Ent) 4231 produced by Enterococcus faecium. The group of 48 rabbits (Hy-Plus breed) was divided into experimental (EG) and control (CG) group. In EG Ent 4231 was applied for 21 days in a dose of 50 μL/animal/day into drinking water. The experiment lasted for 42 days. Samples were collected on day 0-1, day 7, day 21 (3 weeks of administration) and on day 42 (3 weeks after cessation of application) to measure the occurence of Eimeria sp. oocysts. Samples of caecal contents were collected on days 21 and 42 to determine bacterial counts. The phagocytic activity was examined on days 0-1, 21 and 42. On days 21 and 42 the reduction of Clostridium-like sp. was detected in EG (difference 1.53 log10 CFU/g; 1.57 log10 CFU/g) in comparison with CG. In EG on day 7 the decrease of E. coli (difference 1.30 log10 CFU/g) was also noted in comparison with CG. In EG prolonged immunostimulative effect (p<0.001) was observed on day 42 in comparison with CG. The oocysts of Eimeria sp. were reduced in EG comparing with CG at day 42. Enrichment of the diet for rabbits with Ent 4231 did not influence biochemical, zootechnical parameters and the values of caecal content volatile acids during the whole experiment.

In vivo Model Experiment Using Laying Hens Treated with Enterococcus faecium EM41 from Ostrich Faeces and its Enterocin EM41

Abstract Enterococcus faecium EM41 is an isolate from ostrich faeces. It produces a thermo-stable proteinaceous substance, bacteriocin (enterocin) EM41 with the highest inhibition activity in late logarithmic phase of growth (25 600 AU/ml). This strain and its enterocin have not been previously tested in animals. Lohmann Brown laying hens (aged 45 weeks) were involved in this model/pilot experiment, divided into 3 groups 6 birds in each. E. faecium EM41 applied was a variant treated with rifampicin (109 cfu/ml, dose 400 μl/animal/day) to differentiate it from the other enterococci. Partially-purified enterocin EM41 (Ent EM41, dose 40 μl/animal/day) and its producer were applied to water for 21 days. The experiment lasted 35 days. Sampling was performed at days 0-1, 21 (3 weeks of additive application), 35 (2 weeks after cessation of additive application) from every bird. E. faecium EM41 sufficiently colonized the intestinal tract of laying hens from the initial concentration 109 cfu/g, its count reached 4.30 log cfu/g at day 21. PCR genotypization confirmed the identity of the EM41 strain with the species Enterococcus faecium. E. faecium EM41 and its enterocin EM41 showed antimicrobial effects demonstrated by reduction of coagulase-positive and coagulase-negative staphylococci, coliforms, Pseudomonas spp., Aeromonas spp. and Campylobacter spp. The hens were Salmonella spp. free. After administration of both additives, phagocytic activity was stimulated with a significant increase. The additives did not negatively influence biochemical and haematological parameters or weight gains.

ANTIBACTERIAL ACTIVITY OF OREGANO AND SAGE PLANT EXTRACTS AGAINST DECARBOXYLASE-POSITIVE ENTEROCOCCI ISOLATED FROM RABBIT MEAT

The effect of plant extracts (sage, oregano) against decarboxylase-positive enterococci from rabbit back limb meat was reported in this study. O regano plant extract inhibited the growth of all 34 tested enterococci (the inhibitory zones: 12 to 45 mm). The growth of the majority of strains (n=23) was inhibited by oregano plant extract (the high size inhibitory zones (higher than 25 mm). The growth of 11 strains was inhibited by oregano extract reaching medium size inhibitory zones (10 to 25mm). The most sensitive strain to oregano extract was E. faecium M7bA (45 mm). Sage extract was less active against tested enterococci (n=16) reaching lower inhibitory zones (up to 10 mm) . doi:10.5219/239 Normal 0 21 false false false SK X-NONE X-NONE

MICROBIAL STATUS AND QUALITY OF RABBIT MEAT AFTER RABBITS FEED SUPPLEMENTATION WITH PHYTO-ADDITIVES

Nowdays, there is an increasing interest in public health issue due to consumption of healthy and nutritive food, e.i. rich in proteins, low in cholesterol and lipid contents. The aim of this study was to examine if oregano, sage and Eleutherococcus senticosus extracts, commercial Xtract as well can influence microbial status of rabbit meat after their supplementation of rabbit feed. Reduction of enterococci, coagulase-negative staphylococci and Staphylococcus aureus after feed supplementation by the sage and oregano was more detectable at the end of the experiment (at day 42) than after their application (at day 21). In animals with Xtract addition, antibacterial effect has been noted already at day 21. Our in vivo results confirmed in vitro antibacterial effect of the tested extracts and showed that maintaining of rabbit meat quality by plant extracts is very promising.